guest ::
| Home > Publications database > Transport der reaktiven Stoffe Eosin, Uranin und Lithium in einem heterogenen Grundwasserleiter |
| Home > Publications database > Transport der reaktiven Stoffe Eosin, Uranin und Lithium in einem heterogenen Grundwasserleiter |
| Book/Report | FZJ-2019-01853 |
1997
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
Jülich
Please use a persistent id in citations: http://hdl.handle.net/2128/21830
Report No.: Juel-3354
Abstract: To predict the movement of a contaminant plume in an aquifer is still a task of great uncertainty. This uncertainty is generally attributed to an insufficient understanding of the chemical reaction processes and/or to the natural aquifer heterogeneities. In an integrated approach of field experiments, laboratory experiments and numerical simulations, the transport of the weakly reactive solutes eosin, uranin and lithium was investigated at a test site near the Research Center in Jülich. The field scale transport behavior of the solutes was studied by large scale tracer tests. To characterize aquifer heterogeneities, in-situ and laboratory measurements were performed. In-situ measurements covered about 1500 flowmeter measurements and 90 determinations of the groundwater flow velocity by the borehole method. The spatial variability of hydraulic and physico-chemical parameters was further determined on 400 sediment samples. These parameters included: grain size distribution, calculated hydraulic conductivity, unconformity and as physico-chemical parameters the organic carbon content, specific surface and the cation exchange capacity. Furthermore sorption coefficients were measured on 75 sediment samples for uranin and lithium. The statistical evaluation of these data showed that the hydraulic heterogeneity was larger but in the same order of magnitude as the physico-chemical heterogeneity. A weak negative correlation was observed between the hydraulic and physicochemical parameters. Both characteristics had comparable spatial structures as indicated by vertical correlation lengths of a few decimeters. fihe influence of aquifer heterogeneities (hydraulic conductivity and sorption parameters) an die transport behavior was investigated with stochastic numerical models. For uranin whichshowed a nonlinear sorption isotherm, die variability of sorption parameters increased die uncertainty in predicting die plume arrival time while the shape of the plume was hardly affected. Although this approach of stochastic modeling allowed to consider both - the influence of hydraulic and of physico-chemical aquifer heterogeneities, there was still an obvious discrepancy between die simulated and the observed tracer movement. Laboratory and field observations suggest that diese discrepancies are caused by chemical reaction processes like non-reversible sorption and relative slow sorption kinetics.
|
The record appears in these collections: |
PDF
PDF (PDFA)